unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 StdCtrls;
type
 TForm1 = class(TForm)
  Edit1: TEdit;
  Button1: TButton;
  Label1: TLabel;
  Label2: TLabel;
  procedure Button1Click(Sender: TObject);
 private
  { Private declarations }
 public
  { Public declarations }
 end;
var
 Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
var
 driver:pchar;
 sec1, byt1, cl1, cl2:longword;
begin
 driver:=pchar(edit1.text);//要显示的驱动器名
 GetDiskFreeSpace(driver, sec1, byt1, cl1, cl2);
 cl1 := cl1*sec1 * byt1;
 cl2 := cl2*sec1 * byt1;
 Label1.Caption:= '该驱动器总共容量' + Formatfloat('###,##0',cl2) + '字节';
 Label2.Caption := '该驱动器可用容量' + Formatfloat('###,##0',cl1) + '字节';
end;
end.